Java tutorial
/* * * Copyright 2013 Netflix, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ package com.netflix.http4; import java.io.IOException; import java.net.URI; import java.util.ArrayList; import java.util.List; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; import org.apache.http.Header; import org.apache.http.HttpHost; import org.apache.http.HttpRequest; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.ResponseHandler; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.client.params.ClientPNames; import org.apache.http.client.utils.URIUtils; import org.apache.http.conn.ClientConnectionManager; import org.apache.http.conn.routing.HttpRoute; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager; import org.apache.http.message.BasicHeader; import org.apache.http.params.HttpParams; import org.apache.http.params.HttpProtocolParams; import org.apache.http.protocol.HttpContext; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.netflix.config.DynamicIntProperty; import com.netflix.config.DynamicPropertyFactory; import com.netflix.servo.annotations.DataSourceType; import com.netflix.servo.annotations.Monitor; import com.netflix.servo.monitor.Monitors; import com.netflix.servo.monitor.Stopwatch; import com.netflix.servo.monitor.Timer; /** * Netflix extension of Apache 4.0 HttpClient * Just so we can wrap around some features. * * @author stonse * */ public class NFHttpClient extends DefaultHttpClient { private static final Logger LOGGER = LoggerFactory.getLogger(NFHttpClient.class); protected static final String EXECUTE_TRACER = "NFHttpClient__EXECUTE_REQ"; private HttpHost httpHost = null; private HttpRoute httpRoute = null; private static AtomicInteger numNonNamedHttpClients = new AtomicInteger(); private final String name; ConnectionPoolCleaner connPoolCleaner; DynamicIntProperty connIdleEvictTimeMilliSeconds; private DynamicIntProperty retriesProperty; private DynamicIntProperty sleepTimeFactorMsProperty; private Timer tracer; protected NFHttpClient(String host, int port) { super(new ThreadSafeClientConnManager()); this.name = "UNNAMED_" + numNonNamedHttpClients.incrementAndGet(); httpHost = new HttpHost(host, port); httpRoute = new HttpRoute(httpHost); init(); } protected NFHttpClient() { super(new ThreadSafeClientConnManager()); this.name = "UNNAMED_" + numNonNamedHttpClients.incrementAndGet(); init(); } protected NFHttpClient(String name) { super(new ThreadSafeClientConnManager()); this.name = name; init(); } void init() { HttpParams params = getParams(); HttpProtocolParams.setContentCharset(params, "UTF-8"); params.setParameter(ClientPNames.CONNECTION_MANAGER_FACTORY_CLASS_NAME, ThreadSafeClientConnManager.class.getName()); // set up default headers List<Header> defaultHeaders = new ArrayList<Header>(); defaultHeaders.add(new BasicHeader("Netflix.NFHttpClient.Version", "1.0")); defaultHeaders.add(new BasicHeader("X-netflix-httpclientname", name)); params.setParameter(ClientPNames.DEFAULT_HEADERS, defaultHeaders); connPoolCleaner = new ConnectionPoolCleaner(name, this.getConnectionManager()); this.retriesProperty = DynamicPropertyFactory.getInstance() .getIntProperty(this.name + ".nfhttpclient" + ".retries", 3); this.sleepTimeFactorMsProperty = DynamicPropertyFactory.getInstance() .getIntProperty(this.name + ".nfhttpclient" + ".sleepTimeFactorMs", 10); setHttpRequestRetryHandler(new NFHttpMethodRetryHandler(this.name, this.retriesProperty.get(), false, this.sleepTimeFactorMsProperty.get())); tracer = Monitors.newTimer(EXECUTE_TRACER, TimeUnit.MILLISECONDS); Monitors.registerObject(name, this); } public void initConnectionCleanerTask() { //set the Properties connPoolCleaner.setConnIdleEvictTimeMilliSeconds(getConnIdleEvictTimeMilliSeconds());// set FastProperty reference // for this named httpclient - so we can override it later if we want to //init the Timer Task //note that we can change the idletime settings after the start of the Thread connPoolCleaner.initTask(); } @Monitor(name = "connPoolCleaner", type = DataSourceType.INFORMATIONAL) public ConnectionPoolCleaner getConnPoolCleaner() { return connPoolCleaner; } @Monitor(name = "connIdleEvictTimeMilliSeconds", type = DataSourceType.INFORMATIONAL) public DynamicIntProperty getConnIdleEvictTimeMilliSeconds() { if (connIdleEvictTimeMilliSeconds == null) { connIdleEvictTimeMilliSeconds = DynamicPropertyFactory.getInstance().getIntProperty( name + ".nfhttpclient.connIdleEvictTimeMilliSeconds", NFHttpClientConstants.DEFAULT_CONNECTIONIDLE_TIME_IN_MSECS); } return connIdleEvictTimeMilliSeconds; } @Monitor(name = "connectionsInPool", type = DataSourceType.GAUGE) public int getConnectionsInPool() { ClientConnectionManager connectionManager = this.getConnectionManager(); if (connectionManager != null) { return ((ThreadSafeClientConnManager) connectionManager).getConnectionsInPool(); } else { return 0; } } @Monitor(name = "maxTotalConnections", type = DataSourceType.INFORMATIONAL) public int getMaxTotalConnnections() { ClientConnectionManager connectionManager = this.getConnectionManager(); if (connectionManager != null) { return ((ThreadSafeClientConnManager) connectionManager).getMaxTotal(); } else { return 0; } } @Monitor(name = "maxConnectionsPerHost", type = DataSourceType.INFORMATIONAL) public int getMaxConnectionsPerHost() { ClientConnectionManager connectionManager = this.getConnectionManager(); if (connectionManager != null) { if (httpRoute == null) return ((ThreadSafeClientConnManager) connectionManager).getDefaultMaxPerRoute(); else return ((ThreadSafeClientConnManager) connectionManager).getMaxForRoute(httpRoute); } else { return 0; } } @Monitor(name = "numRetries", type = DataSourceType.INFORMATIONAL) public int getNumRetries() { return this.retriesProperty.get(); } public void setConnIdleEvictTimeMilliSeconds(DynamicIntProperty connIdleEvictTimeMilliSeconds) { this.connIdleEvictTimeMilliSeconds = connIdleEvictTimeMilliSeconds; } @Monitor(name = "sleepTimeFactorMs", type = DataSourceType.INFORMATIONAL) public int getSleepTimeFactorMs() { return this.sleepTimeFactorMsProperty.get(); } // copied from httpclient source code private static HttpHost determineTarget(HttpUriRequest request) throws ClientProtocolException { // A null target may be acceptable if there is a default target. // Otherwise, the null target is detected in the director. HttpHost target = null; URI requestURI = request.getURI(); if (requestURI.isAbsolute()) { target = URIUtils.extractHost(requestURI); if (target == null) { throw new ClientProtocolException("URI does not specify a valid host name: " + requestURI); } } return target; } @Override public <T> T execute(final HttpUriRequest request, final ResponseHandler<? extends T> responseHandler) throws IOException, ClientProtocolException { return this.execute(request, responseHandler, null); } @Override public <T> T execute(final HttpUriRequest request, final ResponseHandler<? extends T> responseHandler, final HttpContext context) throws IOException, ClientProtocolException { HttpHost target = null; if (httpHost == null) target = determineTarget(request); else target = httpHost; return this.execute(target, request, responseHandler, context); } @Override public <T> T execute(final HttpHost target, final HttpRequest request, final ResponseHandler<? extends T> responseHandler) throws IOException, ClientProtocolException { return this.execute(target, request, responseHandler, null); } @Override public <T> T execute(final HttpHost target, final HttpRequest request, final ResponseHandler<? extends T> responseHandler, final HttpContext context) throws IOException, ClientProtocolException { Stopwatch sw = tracer.start(); try { // TODO: replaced method.getQueryString() with request.getRequestLine().getUri() LOGGER.debug("Executing HTTP method: {}, uri: {}", request.getRequestLine().getMethod(), request.getRequestLine().getUri()); return super.execute(target, request, responseHandler, context); } finally { sw.stop(); } } }